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And you ask good questions. 802.11n does NOT require super processing power-it's a matter of the hardware on the wireless card, not the computer it's in. As for the first part of your question, "I don't know" is the best I can give you right now. I have a Core Duo (not C2D) MacBook Pro and I am starting to get interested in this question too. Keep your eyes on the tech reports in the press, and stay tuned here for more updates.
And again, Welcome!